Automatic hoist coupling device

ABSTRACT

An automatic coupling device for attachment to a hoist line, having a throat passage for receiving the bail of an article, such as a concrete bucket; a pivoted throat latch in the throat passage yieldable to the upper movement of the bail, and adapted to support the bail for hoisting; a yoke member and actuating mechanism for automatically opening the throat latch when actuated by the bail.

ijnited States Patent Inventor George F. Johnson Potters Trailer Court, Waverly, Tenn. 37 185 App]. N 0. 88,282

Filed Nov. 10, 1970 Patented Dec. 7, 1971 AUTOMATIC HOIST COUPLING DEVICE 9 Claims, 10 Drawing Figs.

US. Cl. 294/83 R, 294/1 10 R int. Cl ..L B66c 1/34 Field of Search 294/83 R,

[56] References Cited UNITED STATES PATENTS 3,l67,345 1/1965 Dukes 294/83 Primary Examiner- Evon C. Blunk Assistant E.raminer--l. Kenneth Silverman Atlorney--Harrington A. Lackey ABSTRACT: An automatic coupling device for attachment to a hoist line, having a throat passage for receiving the bail of an article, such as a concrete bucket; a pivoted throat latch in the throat passage yieldabie to the upper movement of the bail, and adapted to support the bail for hoisting; a yoke member and actuating mechanism for automatically opening the throat latch when actuated by the bail.

PATENTEU DEC 7 ISTI SHEET 1 0F 3 INVENTORI Gap/2 5 I: LENA JON B 2 2 ATTORNEY AUTOMATIC IIOIST COUPLING DEVICE BACKGROUND OF THE INVENTION This invention relates to an automatic hoist coupling device, and more particularly to a coupling device adapted to be supported by a hoist line for automatically coupling and uncoupling the bail of an article such as a concrete bucket.

In the manipulation of a large concrete bucket containing several yards of concrete, by a crane and hoist line, the hoist line must be manually coupled and uncoupled to the concrete bucket, each time the bucket is picked up and each time the bucket is delivered. In order to couple or uncouple a hoist line to the hail of a bucket, the construction worker must climb upon the bucket and direct or maneuver the crane hook into successful engagement with the bail of the bucket. In a similar manner, when the bucket is delivered to the jobsite, a construction worker must climb upon the bucket and release the crane hook from the bail. Because these concrete buckets are quite large, and even taller than the average height of a construction worker, considerable effort and time is required in mounting the buckets and directing and maneuvering the massive crane hooks. Accidents occurring from the coupling and uncoupling of crane hooks to the bails of concrete buckets are not uncommon.

Automatic coupling devices adapted to be suspended from the hoist line, or the crane hook on the hoist line, for automatic coupling and uncoupling with the bail of the concrete bucket, are known. Such coupling devices are of various constructions, but generally include a frame or housing having a vertical throat passage opening in the bottom of the frame, and provided with a pivoted throat latch for opening and closing the throat passage. These coupling devices include various types of actuating or trigger mechanisms adapted to be actuated by the bail as the coupling device moves relative to the bail of the bucket when supported in a stationary position. Some of these coupling devices have mechanical timing mechanisms which delay the closing of a throat latch after the trigger mechanism is actuated by the bail. If the bail cannot be removed from the coupling device during the time interval provided by the timing device, then the throat latch will close before the bail can be removed. Others of such automatic coupling devices are unduly complicated.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an automatic coupling device, adapted to be supported by a hoist line, for cooperation with the bail of an article, such as a concrete bucket, in which the construction is not too complicated, and which includes no timing mechanism.

Another object of this invention is to provide an automatic hoist coupling device for the bail of a concrete bucket including a throat latch and a trigger mechanism in which the throat latch is alternately opened and closed upon each sequential actuation of the trigger mechanism. The throat latch is positively opened upon one actuation of the trigger mechanism, and permitted to close by gravity upon the next actuation of the trigger mechanism.

Furthermore, if, for some reason, the hail of the bucket is outside the coupling device when the throat latch is closed, the throat latch will yield to the relative upward movement of the bail to permit entry of the bail into the throat passage. After entry of the bail, the throat latch automatically drops to its closed position, without actuating the trigger mechanism.

The trigger mechanism includes a yoke member adapted to be moved upward by engagement with the relatively upward moving bail. The yoke member is connected to the throat latch by a link arm having a lost-motion connection. When the yoke member is raised, the throat latch is also positively raised to an upper open position. The throat latch is maintained in an upper open position by a latch member operative between a latched and unlatched position by a latch actuator connected to the yoke member. Thus, the latch member is moved to a latched position and alternately to an unlatched position upon each upward movement of the yoke member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a front elevation of the coupling device made in accordance with this invention showing the throat latch in closed position coupling the bail of the concrete bucket;

FIG. 2 is a section taken along the line 2-2 of FIG. I;

FIG. 3 is an enlarged section taken along the line 3-3 of FIG. 2;

FIG. 4 is a section taken along the line 4--4 of FIG. 3;

FIG. 5 is an enlarged framentary section, similar to FIG. 4, of the latch member and actuator, with portions broken away to show the latch member in its unlatched, inoperative position;

FIG. 6 is an enlarged fragmentary sectional elevation somewhat similar to FIG. 4showing the latch member and latch actuator in a subsequent operative latched position holding the throat latch in its upward open position;

FIG. 7 is a section taken along the line 7-7 of FIG. 6;

FIG. 8 is a fragmentary section taken along the line 8-8 of FIG. 6;

FIG. 9 is a fragmentary view similar to FIG. 5, showing the latch member in its same latched position disclosed in FIG. 6, but the pawl ratcheted to its original position; and

FIG. 10 is an enlarged section taken along the line 10-10 of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in more detail, the automatic hoist coupling device 10 made in accordance with this invention includes a frame or housing II to which is secured a loop 12 for attachment or engagement with a hoist line, not shown. and specifically with the crane hook secured to the hoist line of a crane. As best disclosed in FIGS. 1 and 3, the frame or housing 11 has a generally forked shape including a pair of spaced walls 13 and 14 defining the throat passage I5 opening through the bottom end of the frame 11. The bottom ends of the walls 13 and 14 diverge .to form guide flanges l6 and 17 for guiding the bail 18 into the throat passage 15.

A throat latch 20 spans the throat passage IS in closed position, as disclosed in FIGS. 1 and 3, by extending transversely through openings 21 and 22 in the walls I3 and I4, respectively. The left end of the throat latch 20 is pivotally connected by pin 24 to the frame 11 sothat it may swing between the closed position disclosed in FIGS. 1 and 3, and the open position disclosed in FIG. 7. In extending across the throat passage IS in its closed position, the throat latch 20 rests upon the bottom edges 25 and 26 of the respective openings or slots 21 and 22, respectively. In this manner. the edges 25 and 26 function as stop members to limit the downward movement of the throat latch 22 in its closed position.

If desired, the throat latch 20 may be counterbalanced by tension springs 28, fixed at their upper ends to brackets 29 mounted on frame I], and at their lower ends to a transverse lift bar 30 extending beneath the throat latch 20 to bias the throat latch 20 upward.

The free end of the throat latch 20 may be provided with a latch finger 32 pivotally mounted on the front face of the throat latch 20 by pin 33 and biased to its normal position disclosed in FIG. 3 by spring 34, for a purpose to be described later.

Spanning the upper portion of the throat passage I5 is a yoke member 35 extending transversely through a pair of vertical guide slots 36. Normally the yoke member 35 rests upon the bottom edges of the slots 36, and the upper edges of the slots 36 limit the upward travel of the yoke member 35. If desired. the yoke member 35 may be connected by a pivot pin 37 to a shock absorber 38, disclosed in the form of a dash pot. The piston rod 39 of the dash pot 38 is connected by pin 40 to the upper portion of the frame 11.

The yoke member 35 is provided with an inverted V-shaped notch 42 for engagement by the bail I8.

The left end of the yoke member 35 is connected by link bars 43 to the throat latch 20. The lower ends of the link bars 43 are pivotally connected by pivot pin 44 to the throat latch 20 between the pivot pin 24 and the free end of the throat latch 20. The upper end portions of the link bars 43 are provided with an elongated slot 45 receiving a pin 46 secured to the left end of the yoke member 35. As noted in FIG. 3, the pin 46 is received against the upper end of the elongated slot 45 when the yoke member 35 is resting in its lowermost inoperative position and while the throat latch 20 is disposed in its lowermost closed position.

Thus, when the yoke member 35 is moved upward by engagement of the V-notch 42 with the bail 18 as the housing 11 is moving down, the throat latch 20 is swung upward about pivot pin 24 by the upward movement of the link arms 43, as best illustrated in FIG. 7. The upward movement of the yoke member 35 is not only limited by the vertical dimensions of the guide slots 36, but also by the limit of upward swinging movement of the throat latch 20 to its open position disclosed in FIG. 7. The upward movement of the throat latch 20 is assisted by the upward biased lift bar 30.

In its upper open position, the throat latch 20 is limited against further swinging movement by the resilient latch stop 48. The latch stop 48 urges the throat latch 20 toward its closed position and prevents it from swinging to the left beyond a true vertical position, so that when the throat latch 20 is free, it will fall by gravity to its original closed position disclosed in FIGS. 1 and 3.

When housing 11 is moved up relative to the bail 18, the yoke member 35 returns to its lower position by gravity. However, because of the lost-motion slot 45, the pin 46 merely rides downward in slot 45 without moving the link bar 43 down. Accordingly, the downward motion of the yoke member 35 effects no positive movement upon the throat latch 20. Nevertheless, when the yoke member 35 returns to its lower position, the throat latch 20 is free to drop down to its closed position, if it is not otherwise held in its upper open position.

In order to hold the throat latch 20 in its raised, open position, as disclosed in FIG. 7, a latch member or latch plate 50 is supported for vertical reciprocal movement upon the passage wall 13 by guide brackets 51. The latch plate 50 is normally held or biased in an elevated, inoperative or unlatched position by springs 52 fixed at their lower ends to latch plate arm 53, and at their upper ends to the upper bracket l. The upper end of the latch plate 50 comprises a cam follower or tang 54 biased into engagement, by springs 52, with a rotary cam member 55 having alternating raised portions or lands 56 and depressed portions or notches 57. Each depressed portion 57 has a radius slightly less than the radius of each land 56. Thus, when a notch 57 engages the tang 54, the springs 52 urge the latch plate 50 upward to an unlatched or inoperative position as disclosed in FIG. 5. However, when the rotary cam member 55 is rotated to an angle which permits the land 56 to engage the cam follower 54, the latch plate 50 is urged downward to a latched position as disclosed in FIGS. 6, 7 and 9. In a latched position, the latch plate 50 depends below the top edge of the opening 21 to engage the free end of the latch finger 32 on the free end of throat latch 20. Thus, when the latch plate 50 is in its operative or latched position, and the throat latch 20 is in its open position, the throat latch 20 is held in its open position as disclosed in FIG. 7, until the latch plate 50 is actuated to rise to its inoperative position. When the latch plate 50 is elevated to its unlatched position, the latch stop 48 urges the throat latch 20 downward to its closed position.

As disclosed in the drawings, the lands 56 and notches 57 are spaced apart to alternate at equal 45 angles. Although the alternating lands 56 and notches 57 are disclosed as ratchet teeth of alternating radii, nevertheless they could have other forms, such as an undulating peripheral cam surface.

In order to rotate the rotary cam member 55, a ratchet 58 is fixed to the cam member 55 and is also provided with teeth spaced at 45 intervals. The ratchet 58 is driven by pawl 60 pivotally supported on pawl carrier 61 in the form of a bellcrank which is joumaled upon the same shaft 62 to which the rotary cam member 55 and ratchet 58 are fixed. The pawl carrier 61 is rotated about the shaft 62 by means of the drive arm member 63, the lower end of which is pivotally connected by pin 64 to the pawl carrier 61, and the upper end of which is connected by pivot pin 65 to the yoke member 35.

The operation of the invention can best be described in terms of the transportation of large concrete bucket from a filling station, that is a station in which the bucket is filled with concrete, to a delivery station on a jobsite where the concrete is to be used.

The device 10 is first connected to the hoist line by attaching the crane hook to the loop 12. The crane operator then maneuvers the hoist line, not shown, until the coupling device 10 is lowered over the bail 18. In this stage of the operation, the throat latch 20 is normally in its raised, open position as disclosed in FIG. 7. Accordingly, as the device 10 is lowered over the standing bail 18, the bail 18 is guided between the diverging guide flanges l6 and 17, until the ball 18 enters the open lower end of the throat passage 15. The operator continues to lower the device 10 until the bail 18 is in its phantom position disclosed in FIGS. 1 and 3. Continued lowering of the device 10 causes the bail 18 to seat in the notch 42 and force upward the yoke member 35.

Since the throat latch 20 and the link arm 43 are already in their raised position, the connecting pin 46 merely rises in the lost-motion slot 45 without affecting the open position of the throat latch 20. However, the upward motion of the yoke member 35 lifts the drive arm member 63 to rotate the pawl carrier 61 and the pawl 60, thus moving the ratchet 58 and cam member 55 through an interval of 45'. During this rotary interval, the cam follower 54 rides from a raised land 56 to a depression or notch 57, thereby permitting the latch plate 50 to move from a latched operative position to an unlatched inoperative position, thus releasing the latch finger 32, and permitting the latch stop 48 to thrust the throat latch 20 down to its closed position as disclosed in FIGS. 1 and 3.

The crane operator then lifts the coupling device 10 to release the yoke member 35 from the bail 18. As the yoke member 35 descends to itslowermost position, the rotation of the pawl carrier 61 is reversed so that the pawl 60 ratchets to its original position as disclosed in FIG. 9, preparatory to driving the ratchet 58 through another 45 interval upon the next actuation of the yoke member 35.

Continued upward movement of the coupling device 10 permits the closed throat latch 20 to engage the now coupled bail 18, and the concrete bucket is transported by the device 10 from the filling station to the jobsite. After the bucket is lowered to a stationary position at the jobsite, again the coupling device 10 is lowered until the bail 18 rises, relatively speaking, from the throat latch 20 to the yoke notch 42, to again engage and thrust upward the yoke member 35. Again the yoke member 35 lifts the drive arm 63 causing the pawl 60 to drive the ratchet 58 and cam member 55 through another interval of 45. However, through this interval, the latch plate 50 is moved from its inoperative unlatched position to its operative latched position where its cam follower 54 engages another subsequent land 56.

Moreover, as the yoke member 35 moves upward, the connecting pin 46, resting against the upper edge of the elongated lost-motion slot 45, also pulls upward the link arm 43 to lift the throat latch 20 from its closed position to its upper, open position. When the throat latch 20 reaches its raised open position, the latch 50 will descend in front of the latch finger 32 to latch the throat latch 20 in its open position. If for some reason the latch plate 50 drops into its latched position prior to the throat latch 20 attaining its fully raised position, the bottom of the latch plate 50 merely depresses the latch finger 32 permitting the latch finger 32 to cam beneath the bottom edge of the latch plate 50 until the latch plate 50 drops into latched position against the free edge of the latch finger 32. The coupling device 10 is then raised until it is free of the ball 18. The coupling device 10 is then returned to the filling station to repeat the sequence of operations.

ln the unlikely event that the coupling device is lowered to couple with the bail 18 while the throat latch 20 is down in its closed position, the bail 18 will merely engage and thrust upward the throat latch 20 until it is in the throat passage and has cleared the throat latch 20, at which time the throat latch will drop by gravity to its original closed position. This operation can be accomplished for coupling the bail 18 without any movement or actuation of the yoke member 35.

Thus, because of the construction of the can members 35 with its alternate lands 56 and depressed notches 57, the latch plate 50 is alternately moved to its operative latched position and inoperative unlatched position upon each actuationor lifting motion of the yoke member 35. Thus, the sequential actuation of the yoke member 35 by the bail 18, or by any other actuating device, will alternately open and close the throat passage 15 by the swingingmovement of the throat latch 20.

What is claimed is:

1. An automatic hoist coupling device for an article having an upstanding bail comprising:

a. a lifting frame having upper and lower ends,

b. means for attaching the upper end of said frame to a hoist line, y

c. a vertically extending throat passage in said frame, said passage opening through the lower end of said frame,

d. a yoke member spanning said throat passage,

e. means mounting said yoke member for limited vertical reciprocal movement in said frame,

f. a throat latch,

g. means mounting said throat latch in said frame for pivotal movement between a closed position spanning said throat passage below said yoke member, and an open position opening said throat passage to free movement of a bail therein,

h. a link member connecting said throat latch and said yoke member, whereby upward movement of said yoke member positively moves said throat latch from said closed position to said open position only,

i. said throat latch being normally biased to its closed position,

j. latch means on said frame adapted, in operative position,

to latch said throat latch in said open position, and

k. actuator means operatively connected to said yoke member and said latch means to sequentially actuate said latch means to alternating operative and inoperative positions for latching and unlatching said throat latch in said open position, upon each upward movement of said yoke member.

2. The invention according to" claim 1 in' which said latch means comprises .a latch member movable between said operative and inoperative position, whereby said latch member in said operative position engages and holds said throat latch in said open position, and in said alternate inoperative position releases said throat latch in said open position.

3. The invention according to claim 2 in which said actuator means comprises cam means operative to alternately move said latch member into operative and inoperative positions upon sequential actuation by said yoke member.

4. The invention according to claim 3 in which said cam means comprises a rotary cam member having alternating lands and depressions, said latch member engaging said cam member, said actuator means including'means for rotating said cam member through an interval between aland and a depression upon each upward movement of said yoke member.

5. The invention according to claim 4 in which said actuator means comprises a ratchet fixed to said rotary cam member and pawl means connected to said yoke member for actuating said ratchet.

6. The invention according to claim 1 in which the closed position of said throat latch is substantially transverse of said throat passage, stop means in said frame for limiting the downward movement of said throat latch to said closed position, upper stop means limiting said open position of said throat latch to a raised position inclined toward said closed position, so that said throat latch, when not latched in said open position, will swing by gravity to said closed position.

7. The invention according to claim 6 in which said upper stop means is yieldable and biases said throat latch against said latch means in operative position when said throat latch is in open position.

8. The invention according to claim 1 in which said link member comprises a link arm having upper and lower ends, said throat latch having a pivoted end and a free end, the lower end of said link bar being pivotally connected to said throat latch between said pivoted end and said free end of said throat latch, and the upper end of said link arm being connected to said yoke member.

9. The invention according to claim 8 in which the upper end of said link arm includes an elongated slot, a pin extending through said slot and fixed to said yoke member, so that said pin engages the upper end of said slot when said throat latch is in closed position and said yoke member is in its lowermost position. 

1. An automatic hoist coupling device for an article having an upstanding bail comprising: a. a lifting frame having upper and lower ends, b. means for attaching the upper end of said frame to a hoist line, c. a vertically extending throat passage in said frame, said passage opening through the lower end of said frame, d. a yoke member spanning said throat passage, e. means mounting said yoke member for limited vertical reciprocal movement in said frame, f. a throat latch, g. means mounting said throat latch in said frame for pivotal movement between a closed position spanning said throat passage below said yoke member, and an open position opening said throat passage to free movement of a bail therein, h. a link member connecting said throat latch and said yoke member, whereby upward movement of said yoke member positively moves said throat latch from said closed position to said open position only, i. said throat latch being normally biased to its closed position, j. latch means on said frame adapted, in operative position, to latch said throat latch in said open position, and k. actuator means operatively connected to said yoke member and said latch means to sequentially actuate said latch means to alternating operative and inoperative positions for latching and unlatching said throat latch in said open position, upon each upward movement of said yoke meMber.
 2. The invention according to claim 1 in which said latch means comprises a latch member movable between said operative and inoperative position, whereby said latch member in said operative position engages and holds said throat latch in said open position, and in said alternate inoperative position releases said throat latch in said open position.
 3. The invention according to claim 2 in which said actuator means comprises cam means operative to alternately move said latch member into operative and inoperative positions upon sequential actuation by said yoke member.
 4. The invention according to claim 3 in which said cam means comprises a rotary cam member having alternating lands and depressions, said latch member engaging said cam member, said actuator means including means for rotating said cam member through an interval between a land and a depression upon each upward movement of said yoke member.
 5. The invention according to claim 4 in which said actuator means comprises a ratchet fixed to said rotary cam member and pawl means connected to said yoke member for actuating said ratchet.
 6. The invention according to claim 1 in which the closed position of said throat latch is substantially transverse of said throat passage, stop means in said frame for limiting the downward movement of said throat latch to said closed position, upper stop means limiting said open position of said throat latch to a raised position inclined toward said closed position, so that said throat latch, when not latched in said open position, will swing by gravity to said closed position.
 7. The invention according to claim 6 in which said upper stop means is yieldable and biases said throat latch against said latch means in operative position when said throat latch is in open position.
 8. The invention according to claim 1 in which said link member comprises a link arm having upper and lower ends, said throat latch having a pivoted end and a free end, the lower end of said link bar being pivotally connected to said throat latch between said pivoted end and said free end of said throat latch, and the upper end of said link arm being connected to said yoke member.
 9. The invention according to claim 8 in which the upper end of said link arm includes an elongated slot, a pin extending through said slot and fixed to said yoke member, so that said pin engages the upper end of said slot when said throat latch is in closed position and said yoke member is in its lowermost position. 